Electrostatic generator.



W. H. CHAPMAN.

ELECTROSTATIC GENERATOR.

APPLICATION man JUNE 12, 1915.

1 1 98,889 Patented Sept. 19, 191.6.

2 SHEETSSHEET I W. H. CHAPMAN.

ELECTROSTATICGENERATOR.

APPLICATION FILED JUNE 12, l9l5.

Patented Sept. 19, 1916.

2 SHEETS-SHEET 2.

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UNITED STATES PATENT OFFICE.

WILLIAM HENRY CHAPMAN, OF PORTLAND, MAINE.

ELECTROSTATIC GENERATOR.

Application filed June 12, 1915.

My invention relates to machines in which certain initial charges of electricity develop other charges by induction on insulating surfaces from which they are collected by comb points or other suitable collectors.

It has for its object the production of a machine in which the inducing charge is constantly maintained of one polarity not liable to reversal, and in which the induced charge is multiplied to an enormous extent. In one embodiment of my invention 1 accomplish this object by maintaining the initial charge always negative and of practically uniform potential by a glass disk revolving slowly in a tray of mercury as described in my co-pending application Serial N 0. 875,397 filed Dec. 4, 191A, and using this charge to induce charges in a very rapidly revolving plate of paper or other insulating material not easily disrupted by centrifugal force positioned adjacent to the glass disk. I have found that the maximum potential is attained on a glass disk revolving in contact with mercury when the disk is revolving at the low speed of 10 to 20 revolutions per minute with a 16 inch plate. This speed is therefore fast enough to enable it to perform its function of eXciter for the rapidly moving plate which receives the induced charges, because the inducing charge is not at all used up in performing its function of inducing charges in surfaces brought near to it no matter how rapidly those surfaces may be presented for action, and the quantity developed is proportional to the surface presented per minute.

The plates in influence machines are usually made of'glass or hard rubber, and the speed of such plates is limited to a few hundred per minute by the danger of disruption by centrifugal force, whereas a paper plate may be run with safety at a speed of several thousand per minute. At the low speed of electrostatic generators as hitherto constructed, a plate of paper could not be successful because of the fact that the charges would leak away too rapidly Specification of Letters Yatent.

Patented Sept. 19, 1916.

Serial No. 33,700.

from its surface to be able to maintain the desired potential, especially in damp weather and the pliability of the paper also would cause it to be attracted against the surface on which the inducing charge is held and thus create enormous friction. When, however, provision is made for a speed of several thousand per minute, a plate of very thin paper is held firmly by centrifugal force, and the electrical leakage becomes insignificant because of the brief interval occupied in carrying the induced charges from the point of its production to the point of collection.

One form of apparatus in which I embody my invention is shown in the accompanying drawing in which Figure 1 is a side elevation of the machine, Fig. 2 is a central vertical section, and Fig. 3 is a plan.

Referring to the drawing, A is a disk of glass or other good insulating material mounted on a shaft S revolving in bearing 13. The lower edge of the disk A revolves in an open tray T containing a body of mercury or other liquefied metal. Collars C. C on the shaft S serve to adjust its position endwise and a relatively large pulley P is secured at its rear end.

D is a stationary glass plate having an inductor shown by dotted lines at E prefe'ably of paper secured to its face. This inductor is kept charged negatively by the plate A revolving close to it. Plate A may revolve either way, although for mechanical convenience it revolves in the direction indicated.

F is a disk of cardboard or paper mounted on a shaft G which is driven at high speed by an electric motor or other source of power, belted to pulley H or connected directly to the shaft. Means are provided for driving the disk A much slower than the disk 13. As here shown the shaft G has a worm V engaging with gear I on the counter shaft I on which is also a small pulley P. The pulley I is connected with the pulley P by a band belt P whereby the shaft S is driven at a much slower speed than the shaft C. The disk F revolves close to stationary plate I) on the opposite side of it from plate A.

D is a stationary plate of glass or other nonconductor having an inductor E, preferably of paper pasted on the surface oppo site to revolving plate F.

JJ are two ordinary comb points connected to ground and KK are ordinary comb points attached to well insulated conductors LL including a sliding rod M.

The operation of the machine is as follows: The plate A revolving in contact with the mercury in the tray T becomes charged negatively and keeps the inductor E charged. negatively. lhe negative charge on E acts by induction on the grounded comb J and draws out positive electricity continuously onto the paper disk E which carries it around to comb K and to inductor in, both of which become charged positively. The positive char e is carried to the inductor E by the paper disk and is absorbed through the projecting points formed on the lower end of the inductor in the same manner as in the ordinary IIoltz influence machine.

The inductor E acts by induction on the grounded comb J and draws out negative electricity continuously onto the paper disk E which carries it around to comb K which becomes charged ne atively. Thus opposing charges are maintained on the conduc tors LL and a stream of sparks will pass between them when the sliding rod M is adjusted to the proper spark gap.

A machine constructed as above having a 16 inch glass disk and an 18 inch diameter paper disk will easily maintain a stream of 8 inch sparks, or even 9 inch under favorable weather conditions.

For X-ray work the arrangement described is best, but for some purposes the combs J and K and inductor E can be dispensed with and the comb K with conductor L put in place of J at the top of disk F where it will develop the maximum positive potential between it and the ground. A higher potential between conductor and ground is thus maintained, but the use of the inductor E adds to the quantity output of the machine, and also to the potential between the two conductors, although the potential from either conductor to ground is less.

In case further multiplication of quantity is wanted, it can be obtained by using more inductors and combs applied to disk F in a manner similar to that shown. It is also feasible to increase the quantity output by using two paper disks, one each side of the glass disk, and separated therefrom by stationary inductor plates. My rapidly rotating paper disk may be used as a means of collecting and multiplying the quantity with any form of exciter other than the form here shown. The machine is exceedingly efficient and there is little or no leakage or waste, the power applied being substantially all utilized in producing the static charge.

It is to be understood that the invention may be embodied in a greatvariety of forms.

I claim:

1. In an electro-static generator the combination of a movable member of insulating material, a receptacle containing a body of conducting liquid in contact with said movable member, an inductor adapted to receive a static charge therefrom and grounded conductors arranged to develop a charge by the inductive action of the charge on said inductor.

2. In an electro-static generator the combination of a movable member of insulating naterial, a receptacle containing a body of con lucting liquid in contact with said movable member, an inductor adapted to receive static charge therefrom, a grounded conductor havin comb points and arranged to develop charge by the inductive action of the charge on said inductor, a disk arranged to rotate adjacent to said comb points, to convey the static charge therefrom and means for collecting the charge from said disk.

In. an electrostatic generator the combination of a movable member of insulating material, a receptacle containing a body of conducting liquid in contact with said movable member, an inductor adapted to receive tatic charge therefrom, a grounded conductor havin comb points and arranged to develop a charge by the inductive action of the charge on said inductor, a disk of paper arranged to rotate adjacent to said comb points, to convey the static charge therefrom and means for collecting the charge from said disk.

4t. In an electro-static generator the combination of an inductor, means for maintaining a continuous static charge therein, a grounded conductor adjacent to said inductor having comb points, a disk of flexible paper arranged to rotate adjacent to said comb points, to convey the static charge from said comb points.

5. In an electrostatic generator the combination of a tray having a body of liquefied metal therein, a disk of insulating material adapted to rotate therein, a plate of insulating material adjacent to said disk, an inductor on said plate, a grounded conductor having comb points adjacent to said inductor, a disk arranged to rotate adjacent to said comb points, to draw the static charge from said comb points and means for collecting the charge from said last named disk.

6. In an electro-static generator the combination of a tray having a body of liquefied metal therein, a disk of insulating material adapted to rotate therein, a plate of insulating material adjacent to said disk, an inductor on said plate, a grounded conductor having comb points adjacent to said inductor,

a collecting disk of imperfectly insulating material arranged to rotate adjacent to said comb points, to draw the static charge from the same and means for collecting the charge from said last named disk and for rotating it more rapidly than said first mentioned disk. 7

7. In an electrostatic generator the combination of a tray having a body of liquefied metal therein, a glass disk adapted to rotate therein, a plate of insulating material adjacent to said disk, an inductor thereon, a grounded conductor having comb points adjacent to said inductor, a paper disk arranged to rotate adjacent to said comb points and means for collecting the charge from said paper disk.

S. In an electrostatic generator the combination of a tray having a body of liquefied metal therein, a disk of insulating material adapted to rotate therein, a plate of insulating material adjacent to said disk, an inductor on said plate, a grounded conductor having comb points adjacent to said inductor, a disk arranged to rotate between said comb points and said plate, to draw the static charge from said comb points and means for collecting the charge from said last named disk.

9. In an electro-static generator the combination of a tray having a body of liquefied.

metal, an exciter disk of insulating material arranged to rotate in contact with said metal, a plate of lnsulating material ad acent to said disk, an inductor thereon, a

grounded conductor having comb points adjacent to said inductor, a distributing disk journaled eccentrically with relation to said eXciter disk to rotate adjacent to said comb points, a stationary plate of non-conducting material adjacent to said distributing disk, an inductor thereon, a grounded conductor having comb points adjacent to said last named inductor and means for collecting the positive and negative charges developed by the two grounded conductors.

In testimony whereof I have affixed my signature.

lVILLIAM HENRY CHAPMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

